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Celestron NexStar GPS alignment issues

Posted: Thu Nov 24, 2022 12:48 pm
by jruckgaber
Hi Folks,

I'm new to this forum, so there may have already been a response to this issue.

I have a Celestron 8 inch NexStar GPS scope. I took it out the other night and attempted the GPS align. I had a bit of an issue initially getting it to find the GPS satellite. After powering off and then back on, it found the satellite.

Once the scope confirms the time of day, it started its alignment process. However, the stars it was looking for (except for Polaris) were not even in the sky at that time of night. They would only appear much later in the evening.

I tried this a couple of times, and same issue occurred.

For example, one of the alignment stars (Capella) was about 20 degrees above the horizon at the time I tried the alignment process. However, after slewing, the scope pointed almost straight overhead for that star.

Again, I tried a couple more times and the scope's pointing was way off.

I then tried a 2 start alignment - same issue.

Some other facts that may be pertinent. I was powering the scope with a fully charged, and relatively new, Celestron PowerTank Lithium battery. It was also cold - about 30 degrees. The scope and battery were sitting outside for over an hour to acclimate to the cold.

Any ideas what might be wrong here?

Thanks,

Jeff

Re: Celestron NexStar GPS alignment issues

Posted: Thu Nov 24, 2022 3:05 pm
by Lady Fraktor
Have you checked the information that was put into the hand controller is accurate?
The GPS will not change DST times, that has to be done manually.

Re: Celestron NexStar GPS alignment issues

Posted: Thu Nov 24, 2022 6:36 pm
by Lady Fraktor
Other issues with the older GPS telescope:
1. Have you used it recently?
These I believe had a coin battery installed (GPS unit) and if it has run down you can try leaving the mount plugged in for 12-24 hours to see if it will re-charge.
If the information is still wrong then you may have to replace the battery. Some models had the battery soldered in place so you will need to de-solder the old before replacing.

2. If it is a Version 4 HC and needs the GPS time/ date update you can get it at www.nexstarsite.com, the HCupdate download files are there.
If needing the cfm file it is on Celestron site.
In the meantime if the time/ date is wrong but co-ordinates are right you can just change the time/ date manually

Re: Celestron NexStar GPS alignment issues

Posted: Fri Nov 25, 2022 1:03 pm
by jruckgaber
thanks Lady Fractor - where is the GPS unit? You are not talking about the hand held remote or are you?

I went to look for the HCUpdate and it's giving me an error when I attempt to execute the *.exe file

Celestron HCupdate (1.1.14) is not allowed to run on Win (6.2)

Setup Aborted!

I have Windows 11 on my laptop - so I'm not sure what this error is telling me.

at any rate - no success.

I will plug in the scope for 12-24 hours to see what happens.

Re: Celestron NexStar GPS alignment issues

Posted: Fri Nov 25, 2022 8:36 pm
by Lady Fraktor
Is you telescope Version 4? The early GPS telescopes could not be updated so important to check.
The version 4 updates can be downloaded to your computer then downloaded to the HC or MC without being connected to the internet.
cfm files you must be online.

In case you need to replace your battery here is the guide.
https://www.nexstarsite.com/Book/Updates/GPSBoard.htm

Re: Celestron NexStar GPS alignment issues

Posted: Sat Nov 26, 2022 2:23 pm
by jruckgaber
Confused. How can I tell if my telescope is version 4?

You indicate version 4 can be downloaded. Version 4 of what software? Isn't that the HCUpdate I mentioned that I'm having an issue with? Or is it something else?

When/if I get it downloaded to my computer, how do I download this to the HC or MC? What is the HC or MC?

I've been looking through my telescope for years - so, I'm pretty knowledgeable about what's in the sky, etc.

What I'm a novice with is this type of stuff related to updating the software for the telescope and some of the terminology you are using.

Please provide clearer instructions.

Re: Celestron NexStar GPS alignment issues

Posted: Sat Nov 26, 2022 8:18 pm
by Lady Fraktor
You go into the utility menu in the HC and it will show the version installed. If a version is not shown the HC is not updateable.
If less than version 4 it is likely the HC cannot be upgraded.
If version 4 you can upgrade both HC and MC using HCupdate and MCupdate available from nexstarsite.com
If version 5 then you can download the proper files from Celestron site using the cfm files.

On nexstarsite it shows you which cable(s) you will need to download depending on version
Version 4 and Version 5 use different programming language so are not compatible with each other.

Re: Celestron NexStar GPS alignment issues

Posted: Sun Nov 27, 2022 4:16 am
by JayTee
The following answers are in addition to the excellent info Lady Fraktor (Gabrielle) has provided.
jruckgaber wrote: Sat Nov 26, 2022 2:23 pmConfused. How can I tell if my telescope is version 4?
Version 4 only relates to the version of your hand controller (HC). The Nexstar site will tell you how to tell the difference.
jruckgaber wrote: Sat Nov 26, 2022 2:23 pmYou indicate version 4 can be downloaded. Version 4 of what software? Isn't that the HCUpdate I mentioned that I'm having an issue with?
Version 4 of the HC software can be downloaded from the Nexstar site. Yes, it is the HCUpdate software. https://www.nexstarsite.com/OddsNEnds/H ... rsion4.htm
jruckgaber wrote: Sat Nov 26, 2022 2:23 pmWhen/if I get it downloaded to my computer, how do I download this to the HC or MC? What is the HC or MC?
Follow the instructions from the link in the previous answer
jruckgaber wrote: Sat Nov 26, 2022 2:23 pmI'm a novice with this type of stuff related to updating the software for the telescope and some of the terminology you are using.
After reading the Nexstar info, you should be a novice no longer. Additionally, MC stands for Motor Controller

Cheers,

Re: Celestron NexStar GPS alignment issues

Posted: Sun Nov 27, 2022 3:44 pm
by jruckgaber
Hi Lady Factor,

So with some trial and error, I got to the version screen and it shows: 1.1 4.5 4.5 10.1. Right after that is displayed, I get a screen that shows No Response with the number 1. When I press Undo, I get No Response with the number 110.1.
I don't know what this all means and the manual is useless.

Also, another problem, possibly.

If I click on the Menu button on the remote and navigate to View Time-Site, when I press the down button, I see GPS Linking Local = 10.40.56 - which is the correct time of day. But, when I press on the down arrow again, I get GPS Linking 04/13/03 - which is obviously the wrong date. But I'm unable to change that date. Could this be explaining my alignment issues?

Thanks for your help here. I hope I can get this resolved!

Jeff

Re: Celestron NexStar GPS alignment issues

Posted: Sun Nov 27, 2022 7:47 pm
by Lady Fraktor
Yes there was a GPS update released in 2019 due to the GPS satellite date rollover, sometimes you can trick the HC by pressing align after the GPS has finished and change the date then.

Looking at the version numbers it seems your HC is not upgrade-able. I would contact Celestron Tech and see if the new Nexstar+ HC will work with your telescope.
Keep those numbers close as they will need to know those.
You may also be able to find a upgrade-able one on ebay or such.

The no response errors may be caused by the gps rollover so try changing the date and see what happens.

Hopefully you can get this worked out and use the telescope again. :)

Re: Celestron NexStar GPS alignment issues

Posted: Wed Nov 30, 2022 3:27 pm
by jruckgaber
Hi Lady Fraktor,

Long story short, I spoke with Celestron technical support and they indicated that my handheld remote needs to be replaced. But the new model of the remote is back ordered till July 2023. I placed an order for it.

For now, he indicated I need to turn GPS off on the telescope and do a 2 star alignment instead. With that method, I can enter the correct date and time, and my latitude and longitude. He said I should be able to do the 2 star alignment after that. Its been cloudy / rainy the past 2 days, so no opportunity to get the scope out.

I also had ordered a replacement GPS battery, but the support person said it's probably not necessary and would need to be soldered in place. That's the last resort.

We'll see how this all goes.

Thanks for you help,

Jeff

Re: Celestron NexStar GPS alignment issues

Posted: Wed Nov 30, 2022 4:20 pm
by Gordon
Glad you at least got some resolution!

Hopefully the two star alignment will do the trick and you can get some use out of the scope.

Be sure to give us a report on how things go!

Re: Celestron NexStar GPS alignment issues

Posted: Wed Nov 30, 2022 8:04 pm
by Lady Fraktor
Hopefully this will take care to keep your telescope operating for much longer!
Sad that it is such a long wait though.
In the meantime you could always look for a used HC on various sites like astromart or the bay of evil ;)

Re: Celestron NexStar GPS alignment issues

Posted: Wed Nov 30, 2022 11:28 pm
by JayTee
I have a number of Celestron hand controllers. They are all interchangeable as long as you stay in the alt az category of mount. Two of these (labeled SLT at the bottom) were obtained on eBay for less than $50. They work perfectly.
20221117_134323.jpg

Disregard the iOptron HC, it muscled its way into this image. The point of the picture is to show you that they all look identical.

Re: Celestron NexStar GPS alignment issues

Posted: Sat Jan 06, 2024 3:44 am
by Herbys
JayTee wrote: Wed Nov 30, 2022 11:28 pm I have a number of Celestron hand controllers. They are all interchangeable as long as you stay in the alt az category of mount. Two of these (labeled SLT at the bottom) were obtained on eBay for less than $50. They work perfectly.

20221117_134323.jpg


Disregard the iOptron HC, it muscled its way into this image. The point of the picture is to show you that they all look identical.
Hi! After a long time abroad I was finally re-united with my Celestron Nexstar 11 GPS telescope, but after my first attempt at using it I realized something was wrong with the GPS since we are definitely not in 2004.

I read through multiple forums and everything seems to point to me needing to replace the hand controller. Your post indicates that the different controllers are interchangeable, but in Celestron's site it specifies that the Nexstar+ controller is not compatible with the NexStar GPS series (even though some of the reviews in the site say it works with this telescope).
Do you know if this is correct? I suspect Celestron just not list the GPS telescopes as compatible because of some physical mounting/cosmetic/feature limitation, even though it works, but since you seem to know your stuff you might be able to confirm whether I'm right or this is not the right controller for my telescope.
If this is the right controller, would I need to also replace the GPS chip inside the base? Otherwise, do you know what options I have so I don't have to forgo all the fancy electronics in my telescope and manually align it every time?

Thank you!

Re: Celestron NexStar GPS alignment issues

Posted: Sat Jan 06, 2024 4:11 am
by Lady Fraktor
It will depend on the HC version.
Some can be, some cannot. Then there are version 4 and version 5.
I believe the GPS telescopes were version 4 so you cannot use a version 5 HC

Re: Celestron NexStar GPS alignment issues

Posted: Sat Jan 06, 2024 5:32 pm
by Renoguy
I also have an old NexStar GPS and am trying to update it. There was a GPS "rollover" issue around year 2009 which makes the older GPS scopes now report the wrong date.

The first thing you should do is find out which version of the hand controller you have. Unless you have a very old one before version 1.6 you can use the hand controller to find the version by pressing "Menu", "Utilities" and scrolling to "Version". You should get two lines of numbers. On the first line mine shows "2.2 4.4 4.4". This means I have a firmware version 2.2 hand controller. The other numbers are the motor control firmware versions for Alt and Az motors. Those are important too. My second line shows "2.2 2.2". I think those are serial bus firmware versions.

The best hand controller for the Nexstar GPS which still allows full GPS alignment is version 4.xx. There are many versions after that, but they do not include GPS alignment since that was eliminated due to a patent lawsuit by Meade. The most recent hand controllers are Nexstar+ units which have a micro USB connection at the bottom (instead of RS-232) and also have a button on the lower left with the Celestron logo. Those will probably work with the NS GPS, especially if you have serial bus version 2.x. I have a Nexstar+ controller and it does work with my NS GPS scope. However, instead of GPS align you must use newer alignment methods such as "StarAlign" which uses any three bright objects you choose. At least the GPS does provide correct time, date (GPS rollover was fixed), and I think location (haven't fully tested yet). I figured I'd try the NexStar+ since I got it from Amazon and have a 30 day return period. I've also been looking for a used version 4.xx hand controller but haven't yet found one available.

Back to the older hand controller. The earliest versions (I think 1.0 and 1.2) apparently cannot be easily upgraded. Version 1.6 can be upgraded to 2.2. 1.6/2.2 can be upgraded to 4.xx but only by opening up the hand controller and reprogramming the two flash memory chips inside.

The last motor control update for the NS GPS series was version 4.06 which is reported on the hand controller as "4.6". The earlier versions will work fine for visual observing, but for long term photography version 4.06 is the best one available. You can upgrade to 4.06 motor control if you have a 4.xx hand controller. I'm not yet certain if my 2.2 hand controller can upgrade the motor control firmware.

Besides the Cloudy Nights site, you can also go to nexstarsite.com which has excellent descriptions about Nexstar telescopes in general, including detailed descriptions about upgrading firmware. You can also downgrade the version which might be necessary for some NS GPS scopes by checking out how at the nexstarsite.com site.

Good luck and let us know what you find since I'm still trying to figure this all out as well.

Re: Celestron NexStar GPS alignment issues

Posted: Tue Jan 09, 2024 11:44 pm
by Herbys
That's amazing information, thank you! I'll report back as soon as I can check my HC version information (the telescope is in an airplane's cargo hold right now, after spending the last fifteen years in the southern hemisphere it's time for it to take a look at the northern half of the universe). I should be able to flash the firmware if needed, but hopefully I'll be and to swap the HC for a more modern one, thank you!

Re: Celestron NexStar GPS alignment issues

Posted: Thu Jan 11, 2024 3:24 am
by Herbys
Hi again! I checked my hand controller, and it reports I have a 2.2 controller version as well, with 4.6 motors.
When you say 2.2 is upgradable, you mean only by re-flashing the existing controller? Will that fix the gps rollover issue? Would I need a new GPS board as well?
Otherwise, can I buy a newer controller? E.g. a Nexstar+, which looks awfully similar to my original Nexstar but with a(n old) mini USB port? Would that give me the three -Star alignment algorithm?
Is there anything else I can upgrade to? Even the Nexstar+: looks a bit dated, with a two-line LCD display, so I wonder if Celestron has released anything newer that is still compatible with the motors on my Nexstar GPS.

Sorry about the many questions, I just want to make sure I don't mess up my beloved (if somewhat neglected) telescope.

Re: Celestron NexStar GPS alignment issues

Posted: Thu Jan 11, 2024 4:08 am
by Lady Fraktor
The GPS rollover issue is a separate update.
A Nexstar+ hand controller MAY work with your mount but will not restore the GPS Align function.

Check out https://nexstarsite.com for information about your specific telescope/ mount and applicable updates.